(a) The supposed acid may be: HA, H2A, H3A, etc.
n(NaOH) = c V = 0.1 mol dm-3 x 0.0317 dm3 = 3.17 × 10-3 mol
(b) From the ideal gas law we can obtain:
ρ1/ρ2 = M1/M2
M(H2) = 2 g mol-1
M(acid) = 30 x 2 = 60 g mol-1
By comparing with (1): v = 1
The acid concerned is a monoprotic acid and its molar mass is 60 g mol-1 .
The acid is acetic acid: CH3−COOH